2 * APEI Boot Error Record Table (BERT) support
4 * Copyright 2011 Intel Corp.
5 * Author: Huang Ying <ying.huang@intel.com>
7 * Under normal circumstances, when a hardware error occurs, the error
8 * handler receives control and processes the error. This gives OSPM a
9 * chance to process the error condition, report it, and optionally attempt
10 * recovery. In some cases, the system is unable to process an error.
11 * For example, system firmware or a management controller may choose to
12 * reset the system or the system might experience an uncontrolled crash
13 * or reset.The boot error source is used to report unhandled errors that
14 * occurred in a previous boot. This mechanism is described in the BERT
17 * For more information about BERT, please refer to ACPI Specification
18 * version 4.0, section 17.3.1
20 * This file is licensed under GPLv2.
24 #include <linux/kernel.h>
25 #include <linux/module.h>
26 #include <linux/init.h>
27 #include <linux/acpi.h>
30 #include "apei-internal.h"
33 #define pr_fmt(fmt) "BERT: " fmt
34 #define ACPI_BERT_PRINT_MAX_LEN 1024
36 static int bert_disable;
38 static void __init bert_print_all(struct acpi_bert_region *region,
39 unsigned int region_len)
41 struct acpi_hest_generic_status *estatus =
42 (struct acpi_hest_generic_status *)region;
43 int remain = region_len;
46 if (!estatus->block_status)
49 while (remain > sizeof(struct acpi_bert_region)) {
50 if (cper_estatus_check(estatus)) {
51 pr_err(FW_BUG "Invalid error record.\n");
55 estatus_len = cper_estatus_len(estatus);
56 if (remain < estatus_len) {
57 pr_err(FW_BUG "Truncated status block (length: %u).\n",
62 pr_info_once("Error records from previous boot:\n");
63 if (region_len < ACPI_BERT_PRINT_MAX_LEN)
64 cper_estatus_print(KERN_INFO HW_ERR, estatus);
66 pr_info_once("Max print length exceeded, table data is available at:\n"
67 "/sys/firmware/acpi/tables/data/BERT");
70 * Because the boot error source is "one-time polled" type,
71 * clear Block Status of current Generic Error Status Block,
74 estatus->block_status = 0;
76 estatus = (void *)estatus + estatus_len;
77 /* No more error records. */
78 if (!estatus->block_status)
81 remain -= estatus_len;
85 static int __init setup_bert_disable(char *str)
91 __setup("bert_disable", setup_bert_disable);
93 static int __init bert_check_table(struct acpi_table_bert *bert_tab)
95 if (bert_tab->header.length < sizeof(struct acpi_table_bert) ||
96 bert_tab->region_length < sizeof(struct acpi_bert_region))
102 static int __init bert_init(void)
104 struct apei_resources bert_resources;
105 struct acpi_bert_region *boot_error_region;
106 struct acpi_table_bert *bert_tab;
107 unsigned int region_len;
115 pr_info("Boot Error Record Table support is disabled.\n");
119 status = acpi_get_table(ACPI_SIG_BERT, 0, (struct acpi_table_header **)&bert_tab);
120 if (status == AE_NOT_FOUND)
123 if (ACPI_FAILURE(status)) {
124 pr_err("get table failed, %s.\n", acpi_format_exception(status));
128 rc = bert_check_table(bert_tab);
130 pr_err(FW_BUG "table invalid.\n");
134 region_len = bert_tab->region_length;
135 apei_resources_init(&bert_resources);
136 rc = apei_resources_add(&bert_resources, bert_tab->address,
140 rc = apei_resources_request(&bert_resources, "APEI BERT");
143 boot_error_region = ioremap_cache(bert_tab->address, region_len);
144 if (boot_error_region) {
145 bert_print_all(boot_error_region, region_len);
146 iounmap(boot_error_region);
151 apei_resources_release(&bert_resources);
153 apei_resources_fini(&bert_resources);
158 late_initcall(bert_init);